A 3D technology can present things in a real world to people with a more realistic effect. However, in comparison with 3D display hardware devices, an amount of 3D content is apparently insufficient. Although a 3D device may be used to photograph 3D content, a problem of insufficiency of 3D resources can be effectively solved undoubtedly if abundant existing 2D resources can be converted into 3D resources.
Currently, a depth image based 3D synthesis technology is a more mainstream 2D-to-3D conversion technology. This technology mainly uses a psychological stereoscopic vision of human eyes, which is formed by human visual experience and visual memory during 2D-to-3D conversion. In a 2D image, there are depth cues, such as motion parallax, focusing/defocusing, linear perspective, atmospheric scattering, shadow, blocking, relative height, and relative size. By analyzing these depth cues, depth information in the 2D image may be estimated, and therefore, a corresponding depth image is generated according to the estimated depth information. According to an original view and a depth image corresponding to the original view and by using a depth image based rendering (Depth image based rendering, DIBR) technology, a virtual left view and right view may be synthesized; and by merging the left view and right view and by using a 3D display device, a stereoscopic image having a 3D effect may be obtained.
With maturity of the DIBR technology, the depth image based 3D synthesis technology is extensively studied, and how to accurately estimate depth information of a 2D image becomes crucial to the technology.